Automatic electric power parking brake for a motor vehicle

ABSTRACT

Automatic electric power parking brake system for motor vehicle automatically sets the parking brake when the driver leaves the seat or turns off the engine. It releases the parking brake automatically when the driver sits down and turns on the engine, The device for releasing parking brake includes a driver seat sensor and a double pole double throw igniting switch latching relay to provide a signal causing a motor-operated or coils-operated parking brake to release. The device for setting parking brake is different in an automatic transmission vehicle or in a manual transmission vehicle. A parking shift switch is separately connected to the driver seat sensor and the igniting switch latching relay causing parking brake to be set in an automatic transmission vehicle. A driver&#39;s seat belt buckle switch connects with the driver seat sensor, or the igniting switch latching relay, to set the parking brake in a manual transmission vehicle. A neutral shift switch in an automatic transmission vehicle or a button switch in a manual transmission vehicle can release the parking brake for manual vehicle pushing and towing.

RELATED PATENT APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/005,705 filed Jan. 12, 1998 and U.S. Pat. No. 5,939,795.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to two automatic electric power parking brake systems which are used separately in an automatic transmission motor vehicle and a manual transmission motor vehicle.

[0004] 2. Description of the Prior Art

[0005] Intending to change the hand-operated parking brake for an automatic power one, my prior invention SEAT SENSOR OPERATING SAFETY SYSTEM FOR A MOTOR VEHICLE, U.S. Pat. No. 5,939,795 disclosed a seat-sensor-operated electric parking brake system. It includes a motor to release and to set a cable-operated mechanical handbrake, a releasing signal which is generated by a driver seat sensor and an ignite key switch to operate the motor releasing the brake, a vehicle empty security signal which is generated by both driver seat sensor and passenger seat sensors to operate the motor setting the brake. This system can automatically release the parking brake when the driver is present to turn on engine key, and automatically set the parking brake when both driver and passengers are absent. But we found it still isn't enough. First, either the driver being absent or the engine being turned off, the parking brake needs to be set but it doesn't. Second, when the engine is out of order, it needs a special device to release the automatic power parking brake for moving the vehicle by hand or in tow. Third, driving a manual transmission vehicle is different as driving an automatic transmission vehicle, it needs different power parking brake devices. So the usage of my prior invention is limited. The instant invention will solve these three problems.

[0006] The present invention is the fully automatic power parking brake systems. The handbrake lever can be eliminated but a manual transmission vehicle should include a special finger-push button to release brake when the engine is out of order. For more choices and more safety instruments, we could still attach an additional handbrake-lever-operated parking brake system (HLOPB system). A handbrake lever switch is attached to stop or to activate the automatic electric power parking brake system (AEPPB system) automatically.

SUMMARY OF THE INVENTION

[0007] According to the present invention, Automatic Electric Power Parking Brake includes an electric parking brake device to release and to set parking brake, a device to generate releasing signal or setting signal, and a special releasing switch.

[0008] The electric parking brake device is a motor which will rotate in different directions to pull or release a cable of a cable-operated mechanical parking brake. It can also be replaced by two coils which will pull or release a cable of a cable-operated mechanical parking brake.

[0009] The device to generate releasing signal or setting signal includes a driver present sensor switch, a double pole double throw igniting switch, and an additional Parking Shift switch only in automatic transmission vehicle. They are all connected to the electric parking brake device.

[0010] The special releasing switch is a Neutral Shift switch in automatic transmission vehicle, and is a finger-push switch or a two-point handbrake lever switch in manual transmission vehicle.

BRIEF DESCRIPTION OF THE INVENTION

[0011] The drawings appended hereto are as follows:

[0012]FIG. 1 is a schematic block diagram showing a prior art seat sensor operated electric parking brake which is invented by me;

[0013]FIG. 2 is a perspective view showing a prior art electrically operated parking brake which is invented by me;

[0014]FIG. 3 is a schematic block diagram of the preferred embodiment of the present invention for an automatic transmission motor vehicle;

[0015]FIG. 4 is a schematic block diagram of the preferred embodiment of the present invention for a manual transmission motor vehicle;

[0016]FIG. 5 is a horizontal cross-sectional view of an automatic transmission lever with a shift pattern indicator, to show a P shift switch and a N shift switch which are included in the embodiment of FIG. 3;

[0017]FIG. 6a is a vertical cross-sectional view of parts of a handbrake lever, to show a double pole handbrake lever switch that is included in the embodiment of FIG. 4;

[0018]FIG. 6b is a simple diagram showing a finger-touching switch with a single pole handbrake lever switch replaced a double pole handbrake lever switch;

[0019]FIG. 7 is a perspective view, with parts broken away, showing two coils operated parking brake system, which replaces the motor rotated parking brake system that is included in the embodiment of FIG. 3 and FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020]FIG. 1 is a schematic block diagram showing a prior art seat sensor operated electric parking brake which is invented by me. It includes two passenger seat sensor switches 10 & 20 and a driver seat sensor switch 30, which are separately installed within the first & second passenger seats and the driver seat of the vehicle. The switches 10, 20, and 30 have normally open parts 10A, 20A, and 30A, respectively, and normally closed parts 10B, 20B, and 30B, respectively. A contact 32 of the part 30A is connected to Vcc. In response to the driver seat being occupied, a switch bar 37 electrically connects the normally open contacts 32, 33. In response to the driver seat being unoccupied, the switch bar 37 electrically connects the contacts 32, 36. The normally closed parts 10B, 20B, and 30B have the switch bars 11, 21, and 31, respectively. The switch bars 11, 21, and 31 electrically connect contacts 18 & 19, 28 & 29, and 38 & 39, respectively. The contacts 18 & 19, 28 & 29, and 38 & 39 are normally closed but open in response to the first passenger seat, second passenger seat, and driver seat being occupied, respectively. These contacts are all connected in series, as shown in section 40. The contact 18 is connected to Vcc.

[0021] A double pole double throw latching igniting switch has switch arms 41 and 42, contacts 43 and 45, 44 and 46. When the driver turns on the engine, switch arm 41 electrically connects the normally open contacts 43, 45, and switch 42 does not connect the normally closed contacts 44, 46.

[0022] Contact 43 is connected to contact 33. Contact 45 is connected to a leading-in wire 2 of a parking brake motor 1 (M) through a diode 5. Contact 44 is connected to contact 39. Contact 46 is connected to a leading-in wire 3 of motor 1 through a diode 6.

[0023] As shown in FIG. 1. in connection with FIG. 2, my prior invention includes a normal hand brake system which is simplified with two rear brake discs or drums 57, a fork parking brake cable 58 & 59 and a hand brake lever 60. A cable 56 is additionally fastened to the cable 58 & 59. The other end of the cable 56 is fastened to a lift arm 55 which is connected to a sector gear 53. The sector gear 53 is coupled to a motor 1 (M) through a worm wheel assembly 51. The sector gear 53 is in meshing engagement with the wheel of the assembly 51, the worm of which is coupled to the rotary shaft of the motor 1. The motor 1, the worm wheel assembly 51 and the sector gear shaft 54 of the sector gear 53 are fastened to the vehicle respectively. The motor 1 has two leading-in electric wires 2, 3 and an outgoing electric wire 4 to rotate the motor 1 in different directions when electric current flows from different leading-in wires.

[0024] In response to all the driver seat and the passenger seats being unoccupied and the igniting switch arm 41 being opened, the igniting switch arm 42 being closed (the driver turns off the engine), a vehicle empty security signal voltage is applied to the motor 1. The motor 1 rotates in the forward direction to cause the sector gear 53 to be rotated to pull the cable 56, thus the parking brake is set automatically. in response to the driver seat being occupied and the igniting switch arm 41 being closed, igniting switch arm 42 being opened (the driver starts the engine), a driver present signal voltage is applied to the motor 1. The motor 1 rotates in the reverse direction, such rotation is transmitted through the assembly 51 to rotate the sector gear 53 to release the parking brake.

[0025] It should be understood that the hand brake lever 60 is still controlled by hand to set or to release the parking brake when the driver wants to do it. And, in order to increasing more protection to the passengers, the contact 44 can be changed to connect with the contact 36 (this connection is not shown in FIG. 1). Thus the driver turns off the engine and only the driver seat being unoccupied, the parking brake is set automatically.

[0026] The preferred embodiment of the present invention is described as followings:

[0027]FIG. 3 is a schematic block diagram of the preferred embodiment of the present invention for an automatic transmission motor vehicle. A driver sensor 110 is located into or near the driver seat to sense the seat being occupied or unoccupied. The sensor 110 is a seat occupant weight sensing device or a laser scanning device that senses seat occupant being present or absent. The seat sensor 110 has a sensor switch 111 which has three contacts 112, 113 and 114. When the driver seat is unoccupied, contact 112 is electrically connected with contact 114 and does not electrically connect with contact 113. When the driver seat is occupied, contact 112 is electrically connected with contact 113 and does not electrically connect with contact 114. A double pole double throw latching igniting switch 120 has two switch arms 121, 122 and six electric contacts 123, 124, 125, 126, 127, 128. When the driver turns on the engine, switch arms 121 and 122 connect contacts 123 & 125, and 126 & 128, respectively, but do not connect contacts 123 & 124, and 126 & 127, respectively. When the driver turns off the engine, switch arms 121 and 122 connect contacts 123 & 124, and 126 & 127, respectively, but do not connect contacts 123 & 125, and 126 & 128, respectively.

[0028] As shown in FIG. 3 in connection with FIG. 5, a shift switch device 130 having a P shift switch 131 and a N shift switch 132 of automatic transmission lever 162 with a shift pattern indicator 161 includes a ditch 160 in which the transmission lever 162 moves smoothly by hand, a P shift switch 131 which is located at one side of the ditch 160 at parking shift position, a N shift switch 132 which is located at one side of the ditch 160 at neutral shift position. The P shift switch 131 includes a movable button 131 that can only move into a switch hole 163. Electric contact 133 is located at the bottom surface of button 131. Electric contact 134 is located at the bottom surface of switch hole 163. Two springs 164, 165 are located in switch hole 163 to keep contacts 133, 134 in a normally open condition. The N shift switch 132 includes a movable button 132 that can only move into a switch hole 166. Electric contact 135 is located at the bottom surface of button 132. Electric contact 136 is located at the bottom surface of switch hole 166. Two springs 167, 168 are located in switch hole 166 to keep contacts 135, 136 in a normally open condition. Thus, when the transmission lever 162 moves to parking shift position, button 131 is pressed to make contacts 133, 134 electrically connected. When the transmission lever 162 moves to neutral shift position, button 132 is pressed to make contacts 135, 136 electrically connected.

[0029] As shown in FIG. 3 in connection with FIG. 2, an automatic electric power parking brake system (AEPPB system) for an automatic transmission motor vehicle includes a normal hand brake system which is simplified with two rear brake discs or drums 57, a fork parking brake cable 58 & 59 and a hand lever 60. A cable 56 is fastened to the cable 58 & 59. The other end of the cable 56 is fastened to a lift arm 55 which is connected to a sector gear 53. The sector gear 53 is coupled to a motor 101 (same as motor 1 shown in FIG. 2) through a worm wheel assembly 51. The sector gear 53 is in meshing engagement with the wheel of the assembly 51, the worm of which is coupled to the rotary shaft of the motor 101. The motor 101, the worm wheel assembly 51 and the sector gear shaft 54 of the sector gear 53 are fastened to the vehicle respectively. The motor 101 has two leading-in electric wires 102, 103 (same as wires 2, 3 shown in FIG. 2) and an outgoing electric wire 104 (same as wire 4 shown in FIG. 2) to rotate the motor 101 in different directions when electric current flows from different leading-in wires. The wire 104 is connected to ground. The wire 102 is separately connected to the contact 125 of the igniting switch 120, and to the contact 136 of the N shift switch 132. The wire 103 is connected to the contact 134 of the P shift switch 131. The contact 133 of the P shift switch 131 is separately connected to the contact 114 of the driver sensor switch 111, and to the contact 127 of the igniting switch 120. The contact 123 of the igniting switch 120 is connected to the contact 113 of the driver sensor switch 110. The contact 112 of the driver sensor switch 111, the contact 126 of the igniting switch 120, and the contact 135 of the N shift switch 132 are all connected to a contact 143 of a handbrake lever switch 141. The handbrake lever switch 141 is a simple switch with two contacts 142, 143, which are electrically closed while the handbrake lever 60 is fully pushed down, thus the additional handbrake-lever-operated parking brake system (HLOPK system) is not in use. The handbrake lever switch 141 is electrically opened while the handbrake lever 60 is pulled up, thus the additional HLOPK system is in use. The contact 142 of the handbrake lever switch 141 is connected to Vcc. An indicator 145 (I) of the AEPPB system with a leading-in electric wire 146 and an outgoing electric wire 147 can indicate whether the AEPPB system is activated. The wire 146 is connected to the contact 143 of the handbrake lever switch 141. The wire 147 is connected to ground.

[0030] When the handbrake lever 60 is pulled up, the indicator 145 shows that the additional HLOPK system is in use and the AEPPB system inactivated. The driver must set or release parking brake by hand.

[0031] When the handbrake lever 60 is fully pushed down, the indicator 145 shows that the AEPPB system is activated and the additional HLOPK system is not in use. In response to the driver seat being occupied and the engine turned on, contacts 112, 113 of sensor switch 111 and contacts 123, 125 of igniting switch 120 being electrically connected, electric current flows to wire 102 of motor 101 from Vcc via sensor switch 111 and igniting switch 120. The motor 101 rotates in the reverse direction to release the parking brake automatically. In response to the automatic transmission lever being pushed to parking position, and either the driver turning off the engine or leaving his seat, contacts 133, 134 of P shift switch 131, and either contacts 122, 127 of igniting switch 120 or contacts 112, 114 of sensor switch 111 being electrically connected, electric current flows to wire 103 of motor 101 from Vcc via igniting switch 120 and P shift switch 131, or from Vcc via sensor switch 111 and P shift switch 131. The motor 101 rotates in the forward direction to cause the sector gear 53 to rotate and pull the cable 56, thus the parking brake is set automatically. In response to the automatic transmission lever being pushed to neutral position thus contacts 135, 136 of N shift switch 132 being electrically connected, electric current flows from Vcc to wire 102 of motor 101 via N shift switch 131. The motor 101 rotates in the reverse direction to release the parking brake for manual car pushing and towing.

[0032] It should be understood that the additional HLOPK system is attached for more choices and more safety instruments and it can be omitted. Thus, the handbrake lever 60 and the handbrake lever switch 141 can be eliminated. The AEPPB system works fully automatically.

[0033]FIG. 4 is a schematic block diagram of the preferred embodiment of the present invention for a manual transmission motor vehicle. Similar to the automatic transmission vehicle in FIG. 3, the manual transmission vehicle has a driver sensor 210 with a driver sensor switch 211, a double pole double throw latching igniting switch 220 and a motor 201 with two leading-in electric wires 202, 203 and an outgoing electric wire 204. The driver sensor 210 locates into or near the driver seat to sense the seat being occupied or unoccupied. The sensor switch 211 has three contacts 212, 213, 214. When the driver is occupied, contact 212 is electrically connected with contact 213 but does not electrically connect with contact 214. When the driver is unoccupied, contact 212 is electrically connected with contact 214 but does not being electrically connected with contact 213. The igniting switch 220 has two switch arms 221, 222 and six electric contacts 223, 224, 225, 226, 227, 228. When the driver turns on the engine, switch arms 221, 222 separately connects contacts 223 & 225, 226 & 228 but does not separately connect contacts 223 & 224, 226 & 227. When the driver turns off the engine, switch arms 221, 222 connects contact 223 & 224, and 226 & 227, respectively, but do not connect contacts 223 & 225, and 226 & 228, respectively.

[0034] Because there is not a parking shift in a manual transmission vehicle, when the driver sensor 210 is a seat occupant weight sensing device but not a laser scanning device, if the driver jumps up a little from his seat while driving, AEPPB will be activated and will cause an accident. Thus, there is a driver seat belt buckle switch 216 which works together with a seat occupant weight sensing driver seat sensor 210. There are two electric contacts 217, 218 in buckle switch 216. Contacts 217, 218 are electrically connected when the driver does not buckle seat belt. Contacts 217, 218 are not electrically connected when the driver buckles seat belt. Contact 217 of buckle switch 216 is electrically connected with contact 214 of sensor switch 210.

[0035] As shown in FIG. 4 in connection with FIG. 6a, a three electric contacts of handbrake lever switch 241 includes a touching bar 253 which is fixed to the handle arm 250 of the handbrake lever. The handle arm 250 can be pulled up and down and is fixed to a supporting arm 252 through a shaft 251. The supporting arm 252 is fixed to the floor 254 of the vehicle. Two movable switch buttons 257, 261 located on the floor 254 can separately move into two switch holes 256, 260, which are separately located inside the floor 254. Two electric contacts 243, 244 are located separately at the bottom surface of two movable buttons 257, 261. Two separate contacts on the bottom surface of two switch holes 256, 260 are electrically connected into an electric contact 242. Two springs 258, 259 located inside switch hole 256 keep contacts 243, 242 in a normally open condition. Two springs 262, 263 located inside switch hole 260 keep contacts 244, 242 in a normally open condition. When the handbrake lever is fully pushed down, the end point 255 of touching bar 253 only pushes button 257 but does not push button 261, thus contacts 243, 242 are electrically connected and contacts 244, 242 not electrically connected. The button 261 must be located at a particular position, in which the handbrake lever is pulled up just enough so that the end point 255 moves out of the button 257 to push the button 261, but not enough to set the parking brake by hand. At that time, contacts 244, 242 are electrically connected and contacts 243, 242 are not electrically connected. When the handbrake lever is pulled up continually to set parking brake, the end point 255 of touching bar 253 does not push buttons 257, 261, thus contacts 242 & 243, contacts 242 & 244 both are not electrically connected.

[0036] As shown in FIG. 4 in connection with FIG. 2, similar to the automatic transmission vehicle in FIG. 3, an AEPPB system for a manual transmission motor vehicle includes a normal hand brake system which is simplified with two rear brake discs or drums 57, a fork parking brake cable 58 & 59 and a hand brake lever 60. The other end of the cable 56 is fastened to a lift arm 55 which is connected to a sector gear 53. The sector gear 53 is coupled to a motor 201 (same as motor 1 shown in FIG. 2) through a worm wheel assembly 51. The sector gear 53 is in meshing engagement with the wheel of the assembly 51, the worm of which is coupled to the rotary shaft of the motor 201. The motor 201, the worm wheel assembly 51, and the sector gear shaft 54 of the sector gear 53 are fastened to the vehicle respectively. The motor 201 has two leading-in electric wires 202, 203 (same as wires 2, 3 in FIG. 2) and an outgoing electric wire 204 (same as wire 4 in FIG. 2) to rotate the motor 201 in different directions when electric current flows from different leading-in wire. The electric wire 204 is connected to ground. The electric wire 203 is separately connected to contact 225 of igniting switch 220 and to contact 244 of handbrake lever switch 241. The electric wire 203 is separately connected to contact 227 of igniting switch 220, and to contact 218 of buckle switch 216 when sensor 210 is a seat occupant weight sensing device, or to contact 214 of sensor 210 when it is a laser scanning device. Contact 223 of igniting switch 220 is connected to contact 213 of sensor 210. Contact 212 of sensor 210 and contact 226 of igniting switch 220 are all connected to contact 243 of handbrake lever switch 241. Contact 242 of handbrake lever switch 241 is connected to Vcc. An indicator 245 (I) of the AEPPB system with a leading-in electric wire 246 and an outgoing electric wire 247 can indicate whether the AEPPB system is activated. Electric wire 246 is connected to contact 243 of handbrake lever 241. Electric wire 247 is connected to ground.

[0037] When the handbrake lever 60 is fully pushed down, contacts 242, 243 of handbrake switch 241 are electrically connected, the indicator 245 shows that the AEPPB system is activated and the additional HLOPK system is not in use. In response to the driver seat being occupied and turning on the engine, thus contacts 212, 213 of sensor switch 211 and contacts 223, 225 of igniting switch 220 being electrically connected, electric current flows to wire 202 of motor 201 from Vcc. via sensor switch 211 and igniting switch 220. The motor 201 rotates in the reverse direction to release the parking brake automatically. In response to the driver turning off the engine or the driver unbuckling his seat belt to leave his seat, contacts 226, 227 of igniting switch 220, or contacts 217, 218 of buckle switch 216, and contacts 212, 214 of sensor switch 211 being electrically connected, electric current flows to wire 203 of motor 201 from Vcc. via igniting switch 220 or via sensor switch 211 and buckle switch 216. The motor 201 rotates in the forward direction to set the parking brake automatically.

[0038] When the handbrake lever 60 is pulled up, the indicator 245 shows the additional HLOPK system is in use and the AEPPB system inactivated. The driver must set or release parking brake by hand.

[0039] When the handbrake lever 60 is pushed down to switch 244 to release parking brake but not down to switch 243, the indicator 245 will show that AEPPB system is inactivated, thus contacts 242, 244 of handbrake lever switch 241 being electrically connected, electric current flows from Vcc. to wire 202 of motor 201 to release parking brake for manual car pushing and towing.

[0040] As shown in FIG. 4 in connection with FIG. 6b, the double pole handbrake lever switch 241 can be replaced by a single pole handbrake lever switch 265 and a simple finger-touching switch 270. The purpose of having the switch 270 is to allow the possibility of eliminating the handbrake lever in a vehicle. Similar to the handbrake lever switch 141 in FIG. 3, the handbrake lever switch 265 has two electric contacts 266, 267. They are electrically connected while the handbrake lever is fully pushed down, but not electrically connected when the handbrake lever is pulled up. The finger-touching switch 270 has three contacts 271, 272 and 273. Contact 271 can be electrically connected to contact 272, or to contact 273 by finger touching the switch 270. Contact 267 is connected to contact 271. Contact 266 is connected to Vcc. Contact 272 is separately connected to contact 212 of sensor switch 211, contact 226 of igniting switch 220, and wire 246 of indicator 245. Contact 273 is connected to wire 202 of motor 201. Thus, a single pole switch 265 and a button switch 270 replace the double pole switch 241.

[0041] It should be understood that the HLOPK system is attached for more choices and more safety instruments and it can be omitted. The handbrake lever 60 and the handbrake lever switch 265 can be eliminated but a finger-touching switch 270 must be retained. The AEPPB system will work fully automatically except when the vehicle needs to be pushed or towed.

[0042]FIG. 7 is a perspective view, with parts broken away, showing two coils operated parking brake system replaces a motor rotated parking brake system that is included in the embodiment of FIG. 3 and FIG. 4. Similar to a motor operated parking brake system, it includes a normal hand brake system which is simplified with two rear brake discs or drums 91, a fork parking brake cable 92 & 93 and a hand brake lever 94. A cable 90 is additionally fastened to the cable 92 & 93. The other end of the cable 90 is fastened to a lift plate 87, which is connected to a lift arm 86 through a shaft 68. A spring 85 is fastened to plate 87 to pull it back releasing cable 90. A coil 61 has a leading-in electric wire 62 and an outgoing electric wire 63. It is closed to an end 69 of lift arm 86 and pulls the lift arm 86. A panel 70 has a chip 71, two springs 72, 73 being on one surface and three cylinders 74, 77 and 80 being on the opposite surface. As shown in cylinder 80 with parts broken away, a spring 83 is inside cylinder 80 to push a piston 81, which has its other end protruding outside the cylinder 80 and can be popped up and down. Cylinders 74, 77, and 80 have piston cylinders 75, 78 and 81, respectively. Springs 72, 73 push cylinders 74, 77, and 80 of the panel 70 perpendicularly to plate 87. A box having top surface and bottom surface opened is perpendicular to plate 87 (the box is not shown in FIG. 7). It has two guide rails and makes sure that panel 70 moves. A coil 64 has a leading-in electric wire 65 and an outgoing electric wire 66. It is closed to the chip 71 and pulls cylinders 74, 77, and 80 of panel 70 out of plate 87. Plate 87 has three different length parallel ditches 76, 79 and 82 with different distances to piston cylinders 75, 78 and 81. When coil 61 pulls lift arm 86 and plate 87, piston cylinders 75, 78, 81 will pop into their respective ditches one at a time. The coils 61, 64, the springs 72, 73, 85, the shaft 68, and the box described above are fastened to the vehicle respectively. The outgoing electric wire 63 of coil 61 and outgoing electric wire 66 of coil 64 are all electrically connected to ground.

[0043] As shown in FIG. 3 in connection with FIG. 7, the leading-in electric wire 65 of coil 64 is separately connected to contact 125 of igniting switch 120 and contact 136 of N shift switch 132. The leading-in electric wire 62 of coil 62 is connected to contact 134 of P shift switch 131.

[0044] As shown in FIG. 4 in connection with FIG. 7, the leading-in electric wire 65 of coil 64 is separately connected to contact 225 of igniting switch 220 and contact 244 of handbrake lever switch 241. The leading-in electric wire 62 of coil 61 is separately connected to contact 227 of igniting switch 220 and contact 218 of buckle switch 216.

[0045] In response to the driver seat being occupied and turning on the engine, or, either the transmission lever being pushed to neutral shift in an automatic transmission vehicle or the handbrake lever switch being connected with contact 244 in a manual transmission vehicle, electric current does not flow to coil 61, but flows to coil 64 through wire 65 pulls panel 70 toward coil 64. Panel 70 brings piston cylinders 75, 78 and 81 to leave out of ditches 76, 79 and 82. Spring 85 pulls the lift plate 87 to release cable 90. Thus the parking brake is released automatically. In response to the transmission lever being pushed to parking shift and either the driver seat being unoccupied or the engine being turned off in an automatic transmission vehicle, or either the engine being turning off or the driver leaving his seat in a manual transmission vehicle, electric current does not flow to coil 64, but flows to coil 61 through wire 62 to pull lift arm 86 moving towards coil 61. Lift arm 86 makes lift plate 70 moving to pull cable 90. At the same time springs 72, 73 push panel 70 to make piston cylinders 75, 78 and 81 popped into ditches 76, 79 and 82 one by one. Thus the parking brake is fully set automatically.

[0046] While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it should be understood by those skilled in the art that changes in form and detail may be made therein without departing from the spirit and scope of the invention. 

I claim:
 1. An automatic electric power parking brake system for a motor vehicle with an electrically operated mechanical parking brake, a driver sensor for generating a driver present signal in response to a driver seat being occupied and a driver absent signal in response to a driver seat being unoccupied, and a double pole double throw igniting switch latching relay, comprising: means to provide a signal causing said parking brake being set in response to either said driver sensor generating a driver absent signal or said latching relay being conditioned to turn off engine, electric power means being mechanically connected to said parking brake being electrically connected to said driver sensor by generating said driver present signal, through said latching relay being conditioned to turn engine on to provide a signal causing said parking brake to be release, and said means being connected to set electric power means to provide a signal causing said parking brake to be set.
 2. The system of claim 1 wherein said electric power means includes a motor rotated in two directions with a worm wheel assembly being fastened to a sector gear, said sector gear being connected to a lift arm that is fastened to brake discs or drums through a fork parking brake cable;
 3. The system of claim 1 wherein said electric power means additionally includes a coil-operated electric power means;
 4. The system of claim 3 wherein said electric power means comprises: a lift plate with several parallel ditches on its surface being fastened to brake discs or drums, a coil being electrically connected to said means to pull said lift plate forward to set said parking brake, a panel with several popped out piston cylinders being pressed to said plate by two springs, said cylinders being popped into said ditches one by one, a coil being connected to said means to pull said panel with said cylinders out of said ditches, and a spring pulling said lift plate backward to release said parking brake;
 5. The system of claim 1 wherein said means to provide a signal causing said parking brake being set includes a switch being normally electrically closed but opened while transmission lever being on parking shift, said switch being separately electrically connected to said driver sensor by generating driver absent signal, and to said latching relay being conditioned to turn off engine in an automatic transmission vehicle;
 6. The system of claim 5 wherein a switch being normally opened but being electrically closed while transmission lever being on neutral shift is additionally connected with Vcc and said electric power means to provide a signal causing said parking brake to release;
 7. The system of claim 1 wherein said means to provide a signal causing said parking brake being set includes said electric power means being connected with seat sensor generating a driver absent signal or said latching relay being conditioned to turn off engine in a manual transmission vehicle;
 8. The system of claim 7 wherein said means also additionally includes a driver's seat belt switch being normally electrically closed but being opened while driver seat belt being buckled;
 9. The system of claim 7 wherein a single pole double throw 2-way switch being normally electrically closed to said driver sensor and said latching relay, and normally opened to said electric power means, but conversely being opened to said driver sensor and said latching relay, and being electrically closed to said electric power means, is additionally connected with Vcc and said electric power means to cause said parking brake to release;
 10. The system of claim 1 wherein an additional spare handbrake system comprises: a handbrake lever being connected with a cable to fasten said parking brake, a single pole single throw handbrake lever switch being normally electrically closed to said automatic electric power system while said handbrake lever being pushed fully down, but being opened while said parking brake being set by said handbrake lever;
 11. The system of claim 10 wherein said spare handbrake system includes an indicator to indicate the condition of said automatic electric power system;
 12. The system of claim 10 in connection with claim 7 wherein a single pole double throw handbrake lever switch with a side off position of a manual transmission vehicle additionally comprises: a leading-in electric contact being connected with Vcc, a first outgoing electric contact being connected to said driver sensor and said latching relay, a second outgoing electric contact being connected to said electric power means to release said parking brake, a switch operated by said handbrake lever electrically connecting said leading-in contact to said first contact but disconnecting said leading-in contact to said second contact while said handbrake lever being pulled to a releasing said handbrake position, said switch electrically connecting said leading-in contact to said second contact but disconnecting said leading-in contact to said first contact while said handbrake lever being pulled to a different releasing said handbrake position, and said switch disconnecting said leading-in contact to said first contact and said second contact while said handbrake lever being pulled to set said handbrake. 